This invention relates to vehicle door latches and more particularly to a vehicle door latch having a power operated release mechanism.
An automotive closure, such as a door for an automobile passenger compartment, is hinged to swing between open and closed positions and conventionally includes a door latch that is housed between inner and outer panels of the door. The door latch functions in a well known manner to latch the door when it is closed and to lock the door in the closed position or to unlock and unlatch the door so that the door can be opened manually.
U.S. Pat. No. 4,756,563 granted to Stephen K. Garwood et al Jul. 12, 1988, which is hereby incorporated by reference, discloses a vehicle door latch that has a fork bolt and a spring biased detent that holds the forkbolt in a latched position. The spring biased detent is moved by a manually operated release mechanism that includes an intermittent lever that is pivotally attached to the detent in a depending relationship. The release mechanism further includes a pivotally mounted transfer lever that cooperates with a generally perpendicular tab at the bottom of the intermittent lever. The transfer lever is operated by an inside unlatching lever connected to an inside door handle of the like. When the inside door handle or its equivalent rotates the inside unlatching lever, the intermittent lever is pulled down by the transfer lever moving the detent to a release position where the fork bolt is released allowing the vehicle door to be opened from inside the vehicle.
The release mechanism also includes an outside unlatching lever that is connected to an outside door handle. When the outside door handle or its equivalent rotates the outside unlatching lever, the intermittent lever is pulled down by the transfer lever moving the detent to the release position where the fork bolt is released allowing the vehicle to be opened from inside the vehicle.
The door latch also has a lock mechanism that includes a pivotally mounted lock lever that is connected to the intermittent lever by a pin and slot arrangement. The lock lever is operated by an inside lock lever and an outside lock lever that move the lock lever and the intermittent lever between locked and unlocked positions. The door latch is locked by moving the lock lever and the intermittent lever to the locked position where the tab of the intermittent lever is bypassed by the transfer lever when the transfer lever attempts to unlatch the door latch.
The door latch disclosed in the Garwood ""563 patent which is suitable for its intended purpose, is typical of the conventional approach of having a mechanically operated release mechanism and an independent mechanically operated lock mechanism. The lock mechanism is also power operated in upscale vehicles.
The vehicle door latch of the invention has a power operated release mechanism rather than a mechanically operated release mechanism that is typical of the prior art. The power operated release mechanism eliminates the need for an independent lock mechanism since the vehicle door latch is locked simply by cutting off power to the power operated release mechanism. The vehicle door latch of the invention preferably includes a mechanical override to unlatch the door in the event of a power failure.
Objects, features and advantages of the invention will become apparent from the description below, which is given by way of example with reference to the accompanying drawings.